The present invention relates to a blade re-sharpener. In particular, it relates to a blade re-sharpener for producing a razor sharp, or xe2x80x9cas newxe2x80x9d edge on a blade.
The primary reason for blades becoming blunt is that the extreme edge of the blade bends over. With a cut-throat razor blade, such damage could be corrected with the leather strip. New razor blade heads, however, have their blades surrounded by plastic casings. Such correction of the edge would therefore not be possible.
With continued use, the bent edge will actually break off resulting in a permanently damaged blade. For shaving, such a blade edge is particularly undesirable since shaving with such a blade inevitably results in facial nicks and the like. Therefore it would be usual practice to dispose of such a blade.
Typically, a modern razor blade head will last for a few shaves, and perhaps up to one week of comfortable shaving. Thereafter, the blade, although sharp enough to achieve shave, will not shave as efficiently or as comfortably as when new.
Similar problems occur with other blades, such as those fitted to surgical equipment, and kitchen knives. A means for restoring a clean, sharp edge, which does not require aggressive sharpening with a grinder, for example, would therefore be highly desirable.
An aim of the present invention is to provide a means for restoring a blade to an xe2x80x9cas newxe2x80x9d condition thereby prolonging the life of a blade.
A device to achieve this would desirably function on disposable razor blades, blade heads, kitchen knives, surgical blades and other such blades.
The present invention provides a blade sharpener comprising at least part of an electrochemical cell, wherein, in use, an anode thereof is formed by a blade. The blade can be applied to the sharpener with preferably no, but at least substantially no dismantling of the handle, packaging or casing thereof.
Preferably the sharpener is a domestic blade re-sharpener, be they razor blades or kitchen knives. However, the sharpener could be used in an operating theatre for sharpening surgical blades.
Preferably, the blade sharpener comprises a cathodic plate, an electrolyte and a current source connected, in use, to the cathodic plate and the blade, wherein, in use, the electrolyte immerses both the cathodic plate and the edge of the blade to be sharpened. This forms an electrochemical cell. The process of electrolysis lifts the surface off the edge of the blade to remove the bent over portion thereof, thus resulting in a refreshed, or xe2x80x9cas newxe2x80x9d razor sharp edge.
Preferably, the current source is an external source of current, such as a solar cell, battery or D.C power supply.
Preferably, the blade is a razor blade of a disposable razor head.
Preferably, the anode is formed of a plurality of blades, for example two or three blades in a disposable razor blade head.
Preferably, the cathodic plate is stainless steel or a conductive plastic, or nickel plated copper or solid nickel; little or no electrolytic action, i.e. removal of material, will be experienced by the cathodic plate, and therefore a variety of materials are appropriate. Indeed, the electric circuitry may be formed entirely from conductive plastics, or may even comprise printed circuits. The printed circuits may be conventionally acid etched or may, for example, use conductive inks to make the circuit.
Preferably, the blade sharpener includes a blade holding portion which has insulating means provided thereon to prevent shorting of the electrochemical cell.
Preferably, the electrolyte is a weak solution of sulphuric acid, which will also function as a descaler. Preferably, the electrolyte doubles as a blade sterilizing solution and can have corrosion inhibitors provided therein. The sterilizing substance could be sodium hypochloride. In fact, most ionic solutions will work as the electrolyte equally as well as sulphuric acid.
Two cathodic plates could be provided to sharpen a blade, such as a kitchen knife on two sides thereof. Preferably, the current source would be controlled to switch from one plate to the other plate to provide a uniform sharpening of the blade edge.
Preferably, the gap between the cathodic plates and the blade edge is very small.
In use the current source may be connected to the blade and plate, or plates by means of a spring mounted probe. For a disposable razor blade head, the probe may need to pass through vents provided in the back of the disposable razor blade head.
The current source may be connected to the blade by means of a wire contacting a portion of the front of the blade. For curved blades, the cathodic plate(s) could be made to track/traverse the edge of the blade, or this blade could be made to track/traverse the cathodic plate(s), sharpening at the same time. This allows a disposable razor blade head having a closed back to be sharpened using the present invention. Further, since the connection forming the circuit between the current source and the blade pushes in a direction away from the skin facing surface of the blade, any indentation of the blade caused by the contact against the blade will be in a direction which will not cause potentially hazardous deformation of the blade, such deformations possibly causing skin nicks.